Electric hoist



S. H. LIBBY.

ELECTRIC- HOIST.

APPLICATION FILED'SEPT. 1a, 1911.

1,347,785. Patented July 27, 1920.

Fig. I. 2 /7 20 I /4 M I 45 .37

Fig. 2.

IfiVGZUtOT: 5am H. Libby,

His fi ttovneg.

sA vrH; LIB-BY, OFWEASTYORANVGIE; New JERSEY, AssIenoR T0 GENERAL ELECTRIC COMPANY, 'A conroaa'rron on NEW ELECTRIC HoIs'r.

. Specification of Letterslatent.

YORK.

" Patentedfiuly 1920,

.- App1ication filedf September 13,1917. Serial No. 191,120. a

To all whom it moi concern;

Be it known thatl, SAM-I71. LIBBY, a citizen of the United States, residin at,East range, county of Essex, Stateof cw; Jersey, have invented certainnew and useful Improvements in Electric Hoists, of which the following is,,a specification,

I This invention relates to, electrichoists and has forits object the provision of an improved'type which is rugged, compact and readily manufactured. Morespecifically my invention is designed to 'producea hoist that iiiay be readily transported fro nlplace fii a place orgused in cone nection with I cranes and to the hoisting gear, driving motorv andcontroller are rigidly secured 'to the same supporting frame. Such an arrangement affords. a com-- pact construction and permits thelseveral parts to be operatively securedrtogether about substantially fthesanie' axis of symy Further objectsgof this invention will appear from the following detailed description when taken in connection with the accompanying drawings in which Figure l is a section taken on a vertical plane passing through one form of hoist constructed in accordance with my invention while Fig. 2 'is a vertical section taken on line 2 2 of Big. 1.

details of construc- Fig. 3 is a View showing tion.

Referring to the drawings, 1 denotes a casing which as shown in the drawing is a casting provided with a motor inclosure 5, an inclosure 6 for the hoisting drum 8 and also a housing 7 for the reduction gearing. A stator or stationary part 9 of the motor is secured on the inside of this casing so as to be concentric therewith as shown. This stator is preferably formed by casting the laminations 10 into a frame 11 which after being machined is fitted into the casing and secured thereto. The armature or revolving part 12 of the motor is mounted to revolve within the field frame and drive the drum 8 through the reduction gearing. To this end the motor shaft 13 has a bearing in the sleeve 14: to which sleeve the drum 8 is rigidly secured. The shaft is geared to sleeve 14 through the reduction gearing comprising gear 15 secured to the motor shaft and annular gear 16 suitably secured to the sleeve 14 by means of arms 17. A second annular gear 18 is secured to the end frame 1 9jof the housing I i is mounted to mesh with these. two annular gears. i This double pinion ,20, is-vmounted on a'frame-21 which rotates concentrically with t m sh ft ,13, one of i s: bearings be-. 1ng upon the extension ofrthe sleeve 14 while ts, other bearing is .thein-wardly extending end bearing 22. The tWO. gears constituting the double pinion 20 are of different diameters so that as the double jpinion'rotates around theniotor shaft the-annularfgear 16 will be forcedto rotate since the; other ,annu ar gear18is-fixed. It will be seen, there; fore, that asthemotor shaft rotates, it will Ro a ehe d u le Pi l Q lan s pp t frame around the motor shaft as anaxis andjthat isi nceithe diameters of these pinions are different there will be relative movement between. tl1e.,annn1ar gears meshing 5 therewith," hence the movable. gear :16, and the. sleeveto which it secured will :rotate the drum 8 at reduced speed.

slight axial movement and to this end is provided with a plunger 23 working interiorly of the end bearing 22 arranged to be pressed by a spring 24 against the end of the shaft 13 which projects into the gear housing 7. The spring 24 is kept in place and the tension thereof adjusted by the screw cap 25 which closes the outer end of the end bearing 22. The other end of the shaft 13 has a bearing in the head 28 which is bolted to the inclosure 5.

The friction brake for the motor comprises a disk 30, secured on the end of the motor shaft 13 which projects through head 28, having a friction surface 31 which cooperates with a-stationary friction surface 32 mounted on a spider 33, which two surfaces are pressed together by spring 24 to apply a braking force to the motor shaft which slightly shifts it to the right. The motor shaft is moved to the left so as to re- 13 to have a;

lease the brake by turning the controller which abuts against the end of shaft 13.

This plunger reciprocates in the hub-likeextension 39 of the spider 33, the pin or projection 37 moving in the slot 40 provided therefor in the extension 39. In the form here shown, the controller shaft 35 is sleeved over the outer end of thiseirtens ion and is kept from being displacedby the. cap 41. The controller shaft is False provided with a handle or operating arms 42and contact arms 43 which engage with electrioalcon tacts on the insulating support 4.5. The in-.

sulating support is mounted on the s'pider 33 and a suitable ca'sing46 is provided onthe end of the motor inolosure 5 as a housing for the friction brake and controller. The controller emplo'yed is preferably of that type which controls both directionsof rotation of the motorby moving the handle one way or theother from an off or neutral position. The usual electrical connections-to the motor and resistance elements for the'con-} troller have been omitted from the drawing forthe sake of clearncss.

The mode of operation of my invention as here disclosed is as follows: A'cable which is wound on the hoisting drum 8 having been connected to an object to be hoisted; the motor is started by moving the controller handle 42 from off p'O-' sitionto st'artthe motor; This movement of the controller handle disengages the friction members 31 and 32 ofxthe friction brake by reason "of the axial movement 'of' the shaft 13 against spring 24, permitting the motor toifreely rotate the drum 8.

When the controller again "movefdto spring 24 to move the shaft 13 to the right so that the friction members 31 and 32 again engage and hold. theldrum 8 'inthe position at which'the motor was stopped.

7 ;While I have thus described in detail what is at present the best means known to me for .carrying, out an embodiment of my invention, I would have it understood that it is merely'illus'trative 'and that I do not mean to be limited thereby to' the exact details shown nor in the choice of mechanical equivalentsexcept as defined in my claim hereunto iappended.

What I claim as new and desire to secure by-L'etters' Patent of the United States, is,- electric hoist comprising a casing, an electric motor therein having "its armature longitudinally movable 'and" spring pressed in one direction, "a frictionm'e'mber secured to the armaturesliaft and'cooperating with a stationary member 'tofoi'm a brake, reduction'gearin'gatone end o'fsaid casing a hoistingdrum between the motor and the re- 'duction gearing and driye n 'thereby, a controllensecuredto the oppositeend of the casing, I and means whereby the movement the controller" handle shifts the armature against "the-"spring pressure to release fi i' k In'witness whereof, Ifhavje hereunto set my hand this tenth day of September, 1917.

' "3" I S A'M'H. LIBBY. 

